Time-related changes in neointimal tissue coverage of a novel Sirolimus eluting stent

Interpreting clinical outcomes using different strut thickness in coronary artery disease: insights from vascular imaging analysis

Background

Coronary artery disease is a global health concern that necessitates treatments, such as percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Recent advancements in biodegradable polymer-coated DES have improved long-term outcomes by reducing neointimal hyperplasia. Superior long-term outcomes in patients with ultrathin-strut sirolimus-eluting Orsiro stent (BP-SES) compared with those with thick-strut biolimus-eluting BioMatrix stent (BP-BES) have been shown. This study aimed to explore the mechanisms underlying these differences by using quantitative coronary angiography (QCA) and optical coherence tomography (OCT).

Methods

This sub-analysis of the BIODEGRADE trial, a prospective, randomized, multi-center study, compared BP-SES and BP-BES in patients who underwent PCI between July 2014 and September 2017. Patients with positive stress test results, ischemic symptoms, or those who consented to routine follow-up angiography were included. QCA and OCT were used to evaluate the lumen diameter, cross-sectional areas and stent apposition or coverage. OCT images were analyzed at 1 mm intervals within 5 mm proximal and distal to the stented segment.

Results

Of the 2,341 patients, 689 underwent follow-up angiography between 18- and 36-months post-PCI, and 929 stents were analyzed via QCA. OCT images of 61 participants were available. The BP-SES group exhibited a significantly larger minimal lumen diameter and reduced late lumen loss compared to the BP-BES group (0.34 ± 0.45 mm vs. 0.42 ± 0.44 mm, P = 0.005). OCT analysis showed significantly less neointimal hyperplasia in the BP-SES group (0.04 ± 0.4 mm2 vs. 0.64 ± 0.54 mm2, P < 0.001), with no significant differences in stent strut coverage or inflammation markers, than in the BP-BES group.

Conclusions

QCA and OCT analyses revealed less neointimal growth with BP-SES than with BP-BES, without delayed healing or increased inflammation. These findings underscore the importance of stent design characteristics and suggest that thinner struts may enhance clinical success by reducing restenosis and improving long-term vessel patency.

Clinical Trial Registration

https://clinicaltrials.gov/study/NCT02299011 (NCT02299011).

Recurrent events after acute ST-segment elevation myocardial infarction: predictors and features of plaque progression and stent failure

OBJECTIVES

Patients with acute ST-segment elevation myocardial infarction (STEMI) are at high risk for recurrent coronary events (RCE). Non-culprit plaque progression and stent failure are the main causes of RCEs. We sought to identify the incidence and predictors of RCEs.

METHODS

Eight hundred thirty patients with STEMI were enrolled and followed up for 5 years. All patients underwent blood test analysis at hospital admission, at 1-month and at 12-month follow-up times. Patients were divided into RCE group and control group. RCE group was further categorized into non-culprit plaque progression and stent failure subgroups.

RESULTS

Among 830 patients with STEMI, 63 patients had a RCE (7.6%). At hospital admission, HDL was numerically lower in RCE group, while LDL at both 1-month and 12-month follow-up times were significantly higher in RCE group. Both HDL at hospital admission and LDL at 12-month follow-up were independently associated with RCEs (OR 0.90, 95% CI 0.81-0.99 and OR 1.041, 95% CI 1.01-1.07, respectively). RCEs were due to non-culprit plaque progression in 47.6% of cases, while in 36.5% due to stent failure. The mean time frame between pPCI and RCE was significantly greater for non-culprit plaque progression subgroup as compared to stent failure subgroup (27 ± 18 months and 16 ± 14 months, P  = 0.032).

CONCLUSION

RCEs still affect patients after pPCI. Low levels of HDL at admission and high levels of LDL at 12 months after pPCI significantly predicted RCEs. A RCE results in non-culprit plaque progression presents much later than an event due to stent failure.

A prospective, multicentre first-in-man study of the polymer-free ultrathin-strut BIOrapid stent (BIOVITESSE)

BACKGROUND

Polymer-free drug-coated stents aim to avoid the inflammatory potential of durable polymers, thereby improving the long-term safety profile, and allowing a shorter duration of dual antiplatelet therapy.

AIMS

The BIOVITESSE study was conducted to assess the safety and clinical performance of the BIOrapid polymer-free coronary stent system coated with a novel highly lipophilic sirolimus derivate.

METHODS

BIOVITESSE was a prospective, multicentre, first-in-man study that enrolled subjects with de novo coronary lesions in two cohorts of 33 patients each. The primary endpoint of the first cohort was strut coverage at one month as assessed by optical coherence tomography. The primary endpoint of the second cohort was late lumen loss at nine-month follow-up.

RESULTS

Patients were on average 63 years old (range: 42-87) and 12% had diabetes. The 66 patients had 70 lesions with an average lesion length of 12.5±5.4 mm. Predilatation was performed in 91.4% and post-dilatation in 87.1% lesions; device success was obtained in 97.4%. At one month, 95.2±5.6% (95% CI: 93.2-97.2) of struts were covered and at nine months, in-stent late lumen loss was 0.31±0.30 mm (95% CI: 0.20-0.42) and in-segment late lumen loss was 0.20±0.29 mm. Two target lesion failures occurred (3.1%): one at day 1 (to cover an asymptomatic stent edge dissection), and one at day 288 post-procedure for restenosis. No stent thrombosis was reported during the 12-month study duration.

CONCLUSIONS

The BIOrapid stent system exhibited an excellent safety profile, high strut coverage at one-month, and moderate angiographic efficacy according to the late lumen loss at nine-month angiographic follow-up.

Can an ultrathin strut stent design and a polymer free, proendothelializing probucol matrix coating improve early strut healing? The FRIENDLY-OCT trial. An intra-patient randomized study with OCT, evaluating early strut coverage of a novel probucol coated polymer-free and ultra-thin strut sirolimus-eluting stent compared to a biodegradable polymer sirolimus-eluting stent

BACKGROUND

incomplete strut coverage determines the risk of stent thrombosis in the first months after stent implantation.

AIMS

To evaluate the potential better early healing of a novel probucol coated polymer free ultra-thin strut sirolimus eluting stent (PF-SES). [Clinical trial unique identifier: NCT02785237].

METHODS

Patients with two (angiographically similar) lesions with clinical indication for PCI were enrolled. The investigated stent was compared to a thin strut, bioresorbable polymer, sirolimus eluting stent (BP-SES). Every patient received both stents, one in each lesion, assigned in a randomized sequence. OCT was systematically performed at 3 months. Primary end point was the difference in the proportion of covered struts at 3 months (defined as ≥20 μm of tissue coverage). Secondary end points included differences in percentage of uncovered struts (0 μm coverage), mean strut coverage thickness, and malapposed struts' coverage proportion. Major adverse cardiac events (cardiac death, myocardial infarction, target lesion revascularization, and definite or probable stent thrombosis) at 12 months were also evaluated.

RESULTS

70 patients were included. At 3 months, a consistent and significantly higher strut coverage rate (≥20 μm) was observed in PF-SES as compared to BP-SES, both for well apposed (87.3% versus 79.1%, p < 0.001) and malapposed struts (50.4% vs 37.8%, p 0.00). Uncoverage rate (0 μm) was also significantly lower for the PF-SES (3.1% vs 5.3%, p < 0.001). There were no differences in clinical endpoints.

CONCLUSION

The probucol coated non-polymeric ultra-thin strut sirolimus eluting stent showed a significantly better early strut coverage at 3 months.

Supporting evidence from optical coherence tomography for shortening dual antiplatelet therapy after drug-eluting stents implantation

INTRODUCTION

Dual antiplatelet therapy (DAPT) is required for coronary artery disease treated with drug-eluting stents (DES) implantation. Shortening DAPT duration would be beneficial for patients with high bleeding risk.

AREAS COVERED

Early healing patterns, especially stent strut coverage, assessed by optical coherence tomography (OCT) as a surrogate of neointima have been investigated to make decisions on whether short DAPT would be a safe alternative. This review evaluates the OCT evidence (i.e. neointimal coverage of stent struts within 3 months) for shortening DAPT duration after DES implantation.

EXPERT COMMENTARY

Shortening DAPT (i.e. within 3 months) duration after DES implantation might reduce complications including bleeding without increasing stent thrombosis. However, the optimal duration of DAPT after DES implantation is under discussion. Long-term assessment of short DAPT is required for the decision of the new guidelines regarding the recommended duration of DAPT.

Optical coherence tomography substudy of a prospective multicentre randomised post-market trial to assess the safety and effectiveness of the Firehawk cobalt-chromium coronary stent (rapamycin target-eluting) system for the treatment of atherosclerotic lesions: TARGET All Comers

AIMS

Durable polymer drug-eluting stents (DP-DES) may contribute to persistent inflammation, delayed endothelial healing and subsequent late DES thrombosis. The aim of this optical coherence tomography (OCT) substudy was to compare healing and neointimal coverage of a novel bioabsorbable polymer sirolimus-eluting stent (Firehawk®) (BP-DES) versus the DP-DES (XIENCE) at 90 days in an all-comers patient population.

METHODS AND RESULTS

The TARGET All Comers study is a prospective multicentre randomised post-market trial of 1,656 patients randomised 1:1 to Firehawk or XIENCE at 21 centres in 10 European countries. The TARGET OCT substudy enrolled 36 consecutive patients with 52 lesions at six centres proficient in OCT. Follow-up OCT was performed at three months or prior to revascularisation when occurring before the three-month window. The substudy was designed for non-inferiority of the primary endpoint of neointimal thickness. At follow-up, the mean neointimal thickness by OCT (52 lesions: Firehawk, n=24; XIENCE, n=28), was not significantly different between groups (Firehawk 75.5 μm vs. XIENCE V 82.3 μm) meeting the primary endpoint of non-inferiority (pnoninferiority<0.001). The percentage of stent strut coverage was high in both groups (strut level: 99.9±0.3% vs. 100±0.1%, p=0.26), and the proportion of malapposed struts (1.0±1.6% vs. 1.2±2.0%, p=0.51) was low in both groups.

CONCLUSIONS

Based on OCT, the Firehawk BP-DES has a similar healing response three months after implantation compared to the DP-DES, with near complete strut coverage, moderate neointima formation and minimal strut malapposition.

Outcomes of patients treated with ultrathin-strut biodegradable polymer sirolimus-eluting stents versus fluoropolymer-based everolimus-eluting stents: a meta-analysis of randomised trials

AIMS

The ultrathin-strut biodegradable polymer sirolimus-eluting stent (SES) is a new-generation drug-eluting stent (DES) developed to improve the percutaneous treatment of patients with coronary artery disease. Here, we sought to investigate whether the performance of the ultrathin-strut biodegradable polymer SES is superior to that of the benchmark thin-strut fluoropolymer-based everolimus-eluting stent (EES).

METHODS AND RESULTS

We undertook a study-level meta-analysis of trials in which patients receiving percutaneous coronary intervention (PCI) were randomly assigned to either SES or EES. Primary efficacy and safety outcomes were target lesion revascularisation (TLR) and definite/probable stent thrombosis (ST), respectively. Secondary outcomes were myocardial infarction (MI), death, target lesion failure (TLF) and target vessel failure (TVF). A total of 4,853 patients received a PCI with either SES (n=2,816) or EES (n=2,037) in six trials. After a weighted median follow-up of 12 months, patients treated with SES had a risk of TLR (odds ratio [95% confidence interval]: 1.24 [0.83-1.85], p=0.30), definite/probable ST (0.84 [0.53-1.33], p=0.45) and MI related to the target vessel (0.77 [0.55-1.07], p=0.12) comparable to that of patients treated with EES. We found no significant difference with regard to other secondary outcomes.

CONCLUSIONS

At one-year follow-up, the ultrathin-strut biodegradable polymer sirolimus-eluting stent displays a performance comparable to that of the fluoropolymer-based everolimus-eluting stent.

The BIOFLOW-III Italian Satellite Registry: 18-month results of the Orsiro stent in an all-comer high-risk population

AIMS

We aimed to corroborate clinical evidence on the safety and efficacy of the ultrathin-strut biodegradable-polymer sirolimus-eluting Orsiro stent in an all-comer population including high-risk subgroups.

METHODS

The nationwide, prospective, all-comer BIOFLOW-III Satellite Registry was conducted at 18 Italian sites. High-risk subgroups [diabetes, small vessels (≤2.75 mm), acute myocardial infarction (AMI), and chronic total occlusions (CTOs)] were prespecified. The primary endpoint was target lesion failure (TLF) at 12 months, a composite of cardiac death, target vessel myocardial infarction (MI), emergent coronary artery bypass graft, and clinically driven target lesion revascularization (TLR).

RESULTS

In all, 601 patients were enrolled (31.9% diabetes, 34.6% AMIs) with 736 lesions (37.2% small vessels, 5.7% CTOs, and 15.5% bifurcation lesions). Cumulative TLF rate at 12 months was 4.6% [95% confidence interval (CI) 3.2-6.6]: 6.9% (95% CI 4.1-11.6) in the diabetic patients, 5.0% (95% CI 2.7-9.1) in acute MI subgroup, 4.2% (95% CI 2.3-7.7) in small vessels, and 5.3% (95% CI 1.4-19.7) in CTOs. At 18-month follow-up, TLF, target vessel revascularization, and clinically driven TLR rates in the overall population were 5.2% (95% CI 3.7-7.4), 1.8% (95% CI 1.0-3.3), and 1.6% (95% CI 0.8-3.1), respectively. Probable stent thrombosis rate was 0.5% (95% CI 0.1-1.4), whereas no definite stent thrombosis was observed.

CONCLUSIONS

The study results confirmed the excellent clinical performance of the Orsiro drug-eluting stents at 18 months in the whole all-comer population and in the prespecified high-risk subgroups.

Device specificity of vascular healing following implantation of bioresorbable vascular scaffolds and bioabsorbable polymer metallic drug-eluting stents in human coronary arteries: the ESTROFA OCT BVS vs. BP-DES study

AIMS

We sought to compare vascular healing with bioresorbable everolimus-eluting vascular scaffolds (BVS) and drug-eluting stents with bioabsorbable polymers (BP-DES) at six and 12 months both implanted in the same patients.

METHODS AND RESULTS

This was a multicentre and prospective study including patients with at least two comparable lesions to treat. In every patient both BVS and BP-DES (SYNERGY, Orsiro or BioMatrix Flex) were implanted by lesion randomisation. Patients included were evaluated with optical coherence tomography at six or 12 months (2:1). Finally, 68 patients had an examination at six months and 27 patients at 12 months. The rates of uncovered struts at six months were 1.7±3.2% for BVS and 5.3±5.6% for BP-DES (p=0.0001), and at 12 months 0.48±0.72% and 4.8±5%, respectively (p=0.001). Rates of strut malapposition were significantly lower with BVS. There was no significant intra-patient correlation with BP-DES/BVS for endpoints. Evaginations were more frequent and larger with BVS. Discontinuities in BVS were observed in 19.4% at six months and 14.3% at 12 months.

CONCLUSIONS

Vascular healing with BVS and BP-DES could be more device-specific than patient-specific. At follow-up, BVS presented fewer uncovered or non-apposed struts than BP-DES but more frequent and larger evaginations. Discontinuities in BVS were relatively frequent at both time points.

An optical coherence tomography study of neointimal morphology and strut coverage at different time intervals from implantation of biodegradable polymer-coated sirolimus-eluting stents

OBJECTIVES

The aim of the study was to capture the evolution of neointima after implantation of a biodegradable polymer-coated, sirolimus-eluting, cobalt-chromium coronary stent system (BP-DES).

BACKGROUND

Optical coherence tomography (OCT) suggests that in-stent neointimal morphology influences clinical outcomes after DES implantation.

METHODS

Sixty patients treated with single BP-DES implantation were examined by quantitative coronary angiography (QCA) and OCT at 3, 6, and 12-month follow-up.

RESULTS

Median late lumen loss by QCA (mm) was 0.04 (IQR 0, 0.08), 0.17 (IQR 0, 0.32), and 0.14 (IQR 0.07, 0.31) at 3, 6, and 12-month follow-up respectively (P = 0.03). OCT cross-section multilevel analysis showed uncovered struts in 3.90%, 1.78%, and 0.02% of struts respectively (P = 0.03). The corresponding malapposition rates were 0.12%, 0.04%, and 0%. Lipid-rich neointima was observed only at 12-month follow-up in one restenotic lesion (0.77% cross-sections) that was accountable for the only target vessel revascularization. The homogeneous pattern was prevalent at all three time points, but its incidence displayed an upward trend (3 months: 59%; 6 months: 71%; 12 months: 88%) despite no difference in neointimal volume between 6 and 12 months. Conversely, a trend could be observed of decreasing incidence of heterogeneous pattern as the follow-up length increased.

CONCLUSIONS

In this study of a single-type BP-DES, the majority of stent struts were covered within 3 months from implantation. While the quantitative neointimal accumulation plateaued at 6 months with no further significant increase beyond 6 months, the neointima continued to evolve qualitatively and mature along with better strut coverage between 6 and 12 months after implantation.

Three-months optical coherence tomography analysis of a biodegradable polymer, sirolimus-eluting stent

OBJECTIVE

We aimed to assess early neointimal healing by optical coherence tomography (OCT) 3 months after implantation of the ultrathin Orsiro® sirolimus-eluting stent with biodegradable polymer.

BACKGROUND

New generations of drug-eluting stents with biodegradable polymer have been developed to avoid the continued vascular irritation of durable polymers.

METHODS

In this prospective, open-label study, 34 patients received an Orsiro® sirolimus-eluting stent with biodegradable polymer. In a subgroup of patients (n = 15), the intervention was performed under OCT guidance. All patients underwent OCT-examination at three months. The primary endpoint was 3-month neointimal healing (NIH) score, calculated by weighing the presence of filling defects, malapposed and uncovered struts. Secondary endpoint was maturity of tissue coverage at 3 months.

RESULTS

At 3 months, NIH score was 13.7 (5.4-22), covered struts per lesion were 90% (84-97%), malapposed struts were 2.7% (0.8-5.4%) and rate of mature tissue coverage was 47% (42-53%). No target lesion failure occurred up to 12 months. Patients with OCT-guided stent implantation demonstrated a trend toward earlier stent healing as demonstrated by superior NIH scores (angio guided: 17.6% [8.8-26.4]; OCT-guided: 9.8% [4.0-15.5]; mean difference -8, [95%CI: -18.7-2.9], P = 0.123). This group had significantly more covered struts per lesion (angio-guided: 86% [82-90]; 95% [92-99]; mean difference 9% [95%CI: 3-15], P = 0.001).

CONCLUSION

The Orsiro® sirolimus-eluting stent with biodegradable polymer shows early vascular healing with a high rate of strut coverage at 3-month follow-up. OCT guided stent implantation had a positive impact on early vascular healing.

Optical coherence tomography guidance during bioresorbable vascular scaffold implantation

Bioresorbable vascular scaffold (BRS) represent a revolutionary concept in interventional cardiology. After initial enthusiasm, recent real world registries, including patients with increasing lesion complexity, reported not trivial rates of scaffold thrombosis (ScT). The importance of correct patients selection as well as technical aspects during BRS implantation procedures has been highlighted in several studies suggesting that the high rate of ScT might be related to uncorrected patients/lesions selection together with underutilization of intracoronary imaging guidance leading to suboptimal BRS implantation. The high-resolution power together with the lack of shadowing observed beyond polymer struts makes optical coherence tomography (OCT) the optimal imaging technique to guide BRS implantation and identifies eventually scaffolds failures.

BIOFLOW-III satellite-One-year clinical outcomes of diabetic patients treated with a biodegradable polymer sirolimus-eluting stent and comprehensive medical surveillance

BACKGROUND

Drug-eluting stents with biodegradable polymer might be particularly useful in diabetic patients who are at increased risk for target lesion/target vessel revascularization. We therefore aimed at assessing the safety and performance of a biodegradable polymer sirolimus-eluting stent (BP-SES) in combination with comprehensive optimal medical therapy following coronary interventions.

METHODS

This prospective, multicenter registry was conducted at six centers in Israel. Aside of stent treatment, we aimed for an LDL-C level<70mg/dl; at one and six months post-intervention a diabetic consultancy was required, and follow-up data were collected at six and twelve months. The primary outcome measure was target vessel failure, a composite of cardiac death, target-vessel myocardial infarction and clinically driven target vessel revascularization. Secondary outcomes were target lesion failure, its individual components, and stent thrombosis.

RESULTS

From August 2013 until May 2014, 120 diabetic patients with 158 lesions were treated with a BP-SES. Mean age was 63.9±9.2years, 27.5% were insulin dependent, 28.3% had a history of myocardial infarction, and 47.5% had prior coronary interventions. By visual estimation, lesions were 3.0±0.5mm in diameter and 15.2±7.4mm long; mean stent diameter and length were 3.0±0.5mm and 19.2±6.8mm. Target vessel failure and target lesion failure at 12months occurred in seven (6.4% [95% CI: 3.1-13.0]) and four patients (3.5% [95% CI: 1.3-9.2]), respectively, and definite stent thrombosis in one patient (1.0% [95% CI: 0.1-7.0]).

CONCLUSION

Treatment with a BP-SES demonstrated excellent target-vessel and target-lesion revascularization rates in a high-risk diabetic patient population undergoing catheter-based revascularization followed by intensified medical care.

ANNOTATED TABLE OF CONTENTS

In 120 high-risk diabetic patients with coronary artery stenosis, treatment with the Orsiro sirolimus-eluting stent with biodegradable polymer and comprehensive antidiabetic therapy resulted in excellent clinical outcomes. Target vessel revascularization occurred in 6.4% of patients and target lesion revascularization in 3.5%.